In a large casserole, over medium high heat, melt the butter. When the foaming subsides, add the mushrooms and saute for a minute until they begin to soften. Add the carrots, caraway seeds, paprika, 1/4 cup water, cover and simmer just for 4 to 5 minutes or until the vegetables are just tender.
Add the leftover stew, cover and simmer 10 minutes just to reheat and bring flavors together. Meanwhile parboil the potatoes until tender but not falling apart. Season to the stew to taste with salt and pepper, remove from heat and stir in the sour cream if you wish. Center potatoes in a deep platter and surround them with the stew; garnish potatoes with parsley and meat with pickles.